Lawyers have been instructed to demand the Metropolitan Police withdraw a harassment warning against a journalist who was reprimanded for approaching a convicted fraudster for comment as part of an investigation.

As Croydon Advertiser's chief reporter Gareth Davies was handed the ''prevention of harassment'' notice, a Metropolitan Police officer reportedly told him: ''You say you were just doing your job, but that's what the News of the World and the phone hackers said.''

His newspaper has instructed lawyers to write to the Croydon borough commander, urging that the harassment notice against Mr Davies be withdrawn at the earliest possible opportunity.

"We will be doing all we can to get this ludicrous notice expunged and hope common sense, eventually, prevails."

Mr Davies, 29, who received the letter after emailing self-confessed swindler Neelam Desai for comment on fresh allegations against her, said the ''frustrating'' experience had left him with an impression some police officers feel like ''it's open season for journalists''.

Desai, 33, who is to be sentenced later this month after pleading guilty to a series of frauds, has been additionally accused of conning at least three men, while she was on bail for the previous offences, out of thousands of pounds through a complex dating website scam.

It took three Metropolitan Police officers, based in Gipsy Hill, south London, to visit the Advertiser's head office in Redhill, Surrey, on Monday to serve Mr Davies with a Prevention of Harassment Letter.

The chief reporter yesterday said: ''It gives me the impression there's a feeling among police officers it can be open season for journalists.''

He said it was not until the Croydon Advertiser started to pursue the fresh allegations against Desai that the police took notice - and are now investigating the new claims.

''They were very efficient investigating me but they've been inefficient investigating very serious allegations,'' he said.

Earlier this month, Desai admitted a string of offences at Croydon Crown Court including fraud, running a business while bankrupt, handling stolen goods and selling bogus iPhones.

After the case, the Croydon Advertiser was contacted by a number of victims who said they had been conned while she was on bail.

She allegedly set up a fake profile on an Asian marriage website - Shaadi.com - using the photograph of an attractive marketing manager she stole from Facebook to lure men. One 35-year-old from Leicester claims he lost his business after being conned out of £35,500.

Mr Davies said he first approached Desai to give her a right to reply at her home, in Beulah Grove, Selhurst, on March 4, and then sent two emails detailing the accusations and ''politely'' asking her for a comment.

Desai initially alleged assault against Mr Davies - but has since retracted the accusations.

However, she later claimed the emails she received, and the stories written by the paper, were harassment.